back when I had an R32 GTS I had a fujitsubo legalis R exhaust and a legalis super Ex extractor system. was 2.5" and it droned like a bitch... plus the full stainless system added this tinny noise that made the car sound wierd when it revved.
ended up ditching the legalis R (sold it for a mint too to some brand name hugging buyer on ebay) and getting Tuffy's mufflers in sydney to make me up a custom exhaust. Again done in stainless steel, but this time with a proper resonator to get rid of that metallic noise from the exhaust, and cut down the drone. Still got a little metallic noise from the extractors, but it wasn't that bad. Since they were both 2.5" I didn't really see any change in performance or response, but the change in noise was amazing.
the problem with the fujitsubo, and I suspect with other japanese off the shelf items is that they are designed for turbo AND non turbo applications, not designed for use with an australian cat converter and don't have to meet the same noise emissions as we do. Getting a custom one made up will sort that all out for you.
the extractors and the exhaust: